JP5586420B2 - Video transmission system, transmission processing device, reception processing device, and video transmission method - Google Patents

Description

  Embodiments described herein relate generally to a video transmission system that transmits a video stream of a surveillance camera, for example, a transmission processing device, a reception processing device, and a video transmission method.

  As a conventional video transmission system, for example, in a surveillance system, a video stream photographed by a surveillance camera is recorded on a transmission device side for a certain period, distributed to a reception device through a network, and displayed on a monitor in real time on the reception device side. In this real-time monitor display, when there is a scene of concern, rewind playback is performed by the supervisor.

  By the way, the performance of surveillance cameras has improved, and high quality (especially resolution) video has been obtained. Since this high-quality video has an enormous amount of data, it has been proposed to normally distribute the video with a reduced quality and to read and provide the high-quality video in response to a rewind playback request.

  However, since a transmission band is occupied during a period in which high-quality video is provided, it is extremely difficult to distribute low-quality video that is displayed in real time.

  On the other hand, it is known to transmit a video stream as hierarchically encoded data.

JP 2008-199677 A JP 2006-033507 A

  As described above, in the conventional video transmission system, due to the limitation of the transmission band, it is extremely difficult to simultaneously perform high-quality video distribution while continuing low-quality video distribution.

  According to the embodiment, the video stream is divided into a plurality of hierarchies having different qualities, and each differential video is encoded. Usually, the low-level video data and the middle-level differential video data are distributed in real time, and both are combined and displayed. Accumulate and distribute high-level difference video data for a specified period instead of middle-level difference video data distributed in real time upon request, and store the low-level video data and middle-level difference video data for the corresponding period And composite display.

It is a block diagram which shows the structure of the video transmission system of embodiment. In the said embodiment, it is a conceptual diagram which shows the hierarchical structure of delivery video data. In the said embodiment, it is a conceptual diagram which shows the mode of the band allocation and reproduction | regeneration of hierarchical transmission. In the said embodiment, it is a conceptual diagram which shows the mode of a hierarchy structure and transmission band allocation in the case of delivering a some video stream.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating a configuration of a video transmission system according to an embodiment. Here, a monitoring system that requires real-time display is assumed.

  In FIG. 1, reference numeral 11 denotes a photographing device 11 that houses a surveillance camera. A video stream obtained by the photographing device 11 is hierarchically encoded by the encoding / conversion device 12 and sent to the transmission device 13.

  The hierarchical encoding process of the encoding conversion apparatus 12 is, for example, H.264. The video data is encoded in the H.264 / SVC format. As shown in FIG. 2, the quality of the distribution video is divided into three stages of the lowest quality, the basic quality, and the extended quality. Provides the coded data of the difference video between the basic quality video and the lowest quality video at the extended layer (α) B, and the extended quality video and the basic quality video at the extended layer (β) C. The encoded data of the difference video is provided.

  In the transmission device 13, the video data hierarchically encoded by the encoding / conversion device 12 is input to the hierarchical adjustment unit 131. The layer adjustment unit 131 stores the input video data in the storage unit 132, and selects and outputs the basic quality video encoded data, that is, the video encoded data of the basic layer A and the extended layer (α) B in real time. Further, based on the instruction period and the extended quality designation from the period / quality control unit 133, the video encoding data of the extended layer (β) C corresponding to the extended quality of the instruction period is read from the storage unit 132, and real-time video encoding is performed. Output with data. At this time, the real-time video encoded data is transmitted only to the base layer A so that the entire transmission band falls within the allowable range.

  The encoded video data output from the hierarchy adjustment unit 131 is sent to the transmission processing unit 134, is hierarchically multiplexed in a predetermined transmission format, is sent out from the transmission device 13, and is sent to the reception device 15 via the network 14.

  In the reception device 15, the encoded video data transmitted from the network 14 is received by the reception processing unit 11, divided by hierarchy, and sent to the hierarchy synthesis unit 152. The hierarchical composition unit 152 distinguishes the transmission data according to the hierarchical level and stores the transmission data in the storage unit 153, and performs hierarchical composition for each video and sends it to the display device 16. The display device 16 decodes the input video encoded data and reproduces and outputs it. If there is video encoded data for a specified period together with the real time display video, the display device 16 decodes and reproduces the image and displays it separately with the real time video (separately). It may be displayed on the screen).

  Here, the receiving device 15 includes a period / quality selection unit 154. When the operator monitors the display video and requests for the extended quality video together with the rewind playback, the period / quality selection unit 154 sends the network 14 Is sent to the period / quality control unit 133 of the transmission device 13 via.

  In the above embodiment, the case where the operator inputs a request for rewind playback and extended quality video has been described, but when some abnormality detection is obtained by processing such as motion detection, voice detection, face recognition, It is also possible to automatically request the extended quality video of the corresponding part using this as a trigger.

  FIG. 3 is a conceptual diagram showing a state (a) of transmitting the rewind reproduction video together with the real-time video within the transmission band and a state (b) of the reproduction display in the transmission device 13 and the reception device 15 of the above embodiment. . First, as shown in FIG. 3 (a), the transmission apparatus 13 normally has basic quality video encoded data (the video encoded data of the basic hierarchy A and the extended hierarchy ( α) B differential video encoded data) # 1, # 2,... are transmitted in real time within the transmission band. These data are stored in the storage unit 153 for a certain period.

  Here, it is assumed that the rewind reproduction of the video quality encoded data # 2 of extended quality is requested at time t. When receiving the # 2 rewind playback instruction from the reception device 15, the transmission device 13 reads the extended quality difference image encoded data # 2 from the storage unit 132. At that time, the layer adjustment unit 131 cancels the extension layer (α) of the video encoded data # 5 for real-time transmission and reduces it to only the basic layer with the lowest quality, and the extension read from the storage unit 132 in the transmission band. Quality difference image encoded data # 2 is transmitted.

  The layer synthesizing unit 152 of the receiving device 15 outputs video data # 5 of real-time transmission to the display device 16 with the lowest quality, and stores the difference video encoded data of the extended layer (β) transmitted during that period from the storage unit 153. By combining it with the past video encoded data to be read (video encoded data of the basic layer A and differential video encoded data of the extended layer (α) B), extended quality video encoded data # 2 is generated, Output to the display device 16. As a result, the real-time video is displayed at the minimum quality but without interruption, and the rewind playback is displayed at the extended quality.

  In the above embodiment, the case where the video stream has one channel has been described. However, in a system such as a surveillance camera, video images of a plurality of surveillance cameras are collected and a video stream of a plurality of channels is encoded and transmitted.

  FIG. 4 is a diagram conceptually illustrating a case where a plurality of video streams are transmitted within a limited transmission band (for four layers).

  FIG. 4A shows the hierarchical coding configuration of each of the first video stream a and the second video stream b. As in the hierarchical structure shown in FIG. 2, the basic hierarchy A and the extended hierarchy (α), respectively. B, and extended layer (β) C.

  FIG. 4B is a conceptual diagram showing a state of hierarchical transmission of the first and second video streams a and b subjected to the hierarchical encoding. Usually, the video streams a and b are transmitted together with the basic quality, that is, the basic layer A and the extended layer (α) B, and at least the basic layer data a1, a2, a3,..., B1, b2, b3,. Transmit in real time.

  At time t1, when there is a request for transmission of extended quality for the second video stream b1, the first video stream a2 is limited to the basic layer A (minimum quality), and instead the extended layer (second layer of the second video stream b1 ( β) Transmit C. As a result, the first video stream a2 becomes the lowest quality video, but the second video stream b1 can be displayed as the extended quality video.

  When the transmission of the extended quality of the second video stream b1 is completed at time t2, the basic layer A and the extended layer (α) B of the first video stream a3 are transmitted, and the second video stream b3 is transmitted to the basic layer A. Instead, the extension layer (α) B of the first video stream a2 is transmitted instead. As a result, the second video stream b3 becomes the video of the lowest quality, but the extended layer (α) of the first video stream a2 restricted at time t1 can be interpolated, and at least the first video stream is received on the receiving device side. It is possible to rewind and reproduce a2 with basic quality video.

  Although not shown in detail, when the first and second video streams a and b are respectively transmitted in real time, one stream is limited to the lowest quality video and the other stream is enhanced to the extended quality video. It is also possible.

  As described above, when transmitting a plurality of video streams simultaneously, each of them is hierarchically encoded and the quality of one video stream is reduced in accordance with the demand for extended quality, thereby extending the designated period of the other video stream. Quality data can be transmitted. In other words, for example, when there are scenes of interest while monitoring multiple videos, the scenes are rewound to check for high-quality video. At this time, the video being rewound also looks at the real-time video. Since the video stream that is not being rewound is set to the minimum quality, the video stream being rewound is checked with high quality while maintaining the real-time video quality of the video stream being rewound. be able to.

  In the above embodiment, the difference video that improves the quality of the other video by reducing the quality of one video is provided. However, the basic quality video of the video with the reduced quality cannot be obtained during that period. Therefore, when there is some margin in the transmission band, the extended quality (α) differential video encoded data is transmitted over time and stored in the storage unit 153 on the receiving side. As a result, the receiving device 15 can display at least the basic quality video on the monitor.

  In addition, the said embodiment is not limited as it is, In the implementation stage, a component can be deform | transformed and embodied in the range which does not deviate from the summary. Moreover, an appropriate combination of a plurality of constituent elements disclosed in the above embodiment may be used. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 11 ... Imaging device, 12 ... Encoding device, 13 ... Transmission device, 131 ... Hierarchy adjustment unit, 132 ... Storage unit, 133 ... Period / quality control unit, 134 ... Transmission processing unit, 14 ... Network, 15 ... Reception device, 151: Reception processing unit, 152 ... Hierarchy synthesis unit, 153 ... Storage unit, 154 ... Period / quality selection unit, 16 ... Display device.

Claims (7)

A transmission processing device that transmits a real-time video stream; and a reception processing device that receives and displays the video stream transmitted by the transmission processing device;
The transmission processing device includes:
The video stream is a difference between a basic layer data that is a first quality video, a second quality video that is higher than the first quality, and a first quality video. And the second extended layer data that is the difference between the third quality video having a higher quality than the second quality and the second quality video. Hierarchical encoding means;
Transmitting-side storage means for storing video of a plurality of hierarchical data divided and encoded into the basic hierarchical data and first and second extended hierarchical data;
The base layer data and the first extended layer data of the plurality of layer data are output in real time as the second quality video stream, and the specific video stored by the transmission side storage unit from the reception processing device is output. A hierarchy adjusting unit that stops real-time output of the first extension hierarchy data upon receiving a reproduction request, and outputs second extension hierarchy data of the specific video that has received the reproduction request;
Transmission processing means for transmitting multiplexed data obtained by multiplexing a plurality of hierarchical data output by the hierarchy adjusting means to the reception processing device,
The reception processing device includes:
Receiving processing means for separating and decoding the plurality of hierarchical data from the multiplexed data transmitted by the transmission processing device;
Receiving side storage means for storing a plurality of hierarchical data to be decoded by the reception processing means;
Video reproduction requesting means for transmitting a reproduction request for a specific video stored in the transmission-side storage means to the transmission processing device;
When outputting the real-time video stream, the base layer data separated and decoded by the reception processing means and the first extension layer data are synthesized to generate the real-time video according to the second quality, and the video playback request When the reproduction request for the specific video by the means is made, the reception processing means reads out the basic layer data and the first extension layer data of the specific video separated and decoded by the reception processing means from the reception-side storage means And a layer synthesizing unit configured to generate the specific video with the third quality by combining with the second extension layer data of the specific video to be separately decoded. When there are multiple video streams,
The hierarchical encoding means divides and encodes the plurality of video streams into the plurality of hierarchical data,
The transmission-side storage means stores a plurality of hierarchical data videos obtained for each video stream,
The layer adjustment means outputs, in real time, the basic layer data and the first extended layer data of the plurality of layer data as the second quality image stream for each of the plurality of video streams as the second quality video stream. When a playback request for a specific video is received by designating any of the plurality of video streams stored by the transmission-side storage unit from the device, the first enhancement layer data other than the video stream specified by the playback request Stop real-time output, read out the second extension layer data of the specific video of the video stream specified in the playback request from the transmission side storage means, and output,
The video reproduction requesting means transmits any one of a plurality of video streams accumulated by the transmission side accumulating means and a reproduction request for the specific video to the transmission processing device,
The layer synthesizing unit synthesizes the basic layer data and the first enhancement layer data of the plurality of video streams separated and decoded by the reception processing unit when the real-time video stream is output. Real-time video according to quality is generated, and when a specific video playback request of the specified video stream is requested by the video playback requesting means, the basic layer data and the first extension of the specific video of the video stream specified by the playback request The layer data is read out from the receiving-side storage unit and combined with the second extension layer data of the specific video of the designated video stream that is separated and decoded by the reception processing unit, and the identification based on the third quality is performed. The video transmission system according to claim 1, wherein the video is generated. In a transmission processing device that transmits a video stream of real-time distribution video,
The video stream is a difference between a basic layer data that is a first quality video, a second quality video that is higher than the first quality, and a first quality video. And the second extended layer data that is the difference between the third quality video having a higher quality than the second quality and the second quality video. Hierarchical encoding means;
Transmitting-side storage means for storing video of a plurality of hierarchical data divided and encoded into the basic hierarchical data and first and second extended hierarchical data;
The basic layer data and the first extended layer data among the plurality of layer data are output in real time as the second quality video stream, and the specific video stored in the transmission side storage unit from the reception processing device is reproduced. A layer adjustment unit that stops real-time output of the first extension layer data upon receiving a request, and outputs second extension layer data of the specific video that has received the reproduction request;
A transmission processing apparatus comprising: transmission processing means for transmitting multiplexed data obtained by multiplexing a plurality of hierarchical data output from the hierarchy adjustment means to the reception processing apparatus. When there are multiple video streams,
The hierarchical encoding means divides and encodes the plurality of video streams into the plurality of hierarchical data,
The transmission-side storage means stores a plurality of hierarchical data videos obtained for each video stream,
The layer adjustment means outputs, in real time, the basic layer data and the first extended layer data of the plurality of layer data as the second quality image stream for each of the plurality of video streams as the second quality video stream. When a playback request for a specific video is received by designating any of the plurality of video streams stored by the transmission-side storage unit from the device, the first enhancement layer data other than the video stream specified by the playback request 4. The transmission processing apparatus according to claim 3, wherein real-time output is stopped, and second extension layer data of a specific video of a video stream designated by the reproduction request is read out from the transmission-side storage means and output. . In a reception processing device that receives and displays a real-time video stream transmitted from the transmission processing device,
The transmission processing device is
The video stream is a difference between a basic layer data that is a first quality video, a second quality video that is higher than the first quality, and a first quality video. Divided into the extension layer data, and the second extension layer data that is the difference between the third quality video and the second quality video that are higher in quality than the second quality,
Storing videos of a plurality of hierarchical data divided and encoded into the basic hierarchical data and first and second extended hierarchical data;
When the basic hierarchy data and the first extended hierarchy data among the plurality of hierarchy data are output in real time as the second quality video stream, and the reproduction request for the specific video to be stored is received, the first hierarchy data is received. Stop the real-time output of the extended layer data, and output the second extended layer data of the specific video that has received the playback request,
When transmitting multiplexed data obtained by multiplexing the plurality of hierarchical data to be output,
Reception processing means for separating and decoding the plurality of hierarchical data from the multiplexed data transmitted by the transmission side processing device ;
Receiving side storage means for storing a plurality of hierarchical data to be decoded by the reception processing means;
Video reproduction request means for transmitting a reproduction request for a specific video stored in the transmission processing device to the transmission processing device;
When outputting the real-time video stream, the base layer data separated and decoded by the reception processing means and the first extension layer data are synthesized to generate the real-time video according to the second quality, and the video playback request When the reproduction request for the specific video by the means is made, the reception processing means reads out the basic layer data and the first extension layer data of the specific video separated and decoded by the reception processing means from the reception-side storage means And a layer synthesizing unit configured to generate the specific video with the third quality by combining with the second extended hierarchical data of the specific video that is separated and decoded in step (b). The video stream is plural, and the transmission processing apparatus divides and encodes the video streams into the hierarchical data, and transmits video of the hierarchical data obtained for each video stream on the transmission side. Accumulate in the accumulation means ,
For each of the plurality of video streams, the basic layer data and the first extended layer data among the plurality of layer data are output in real time as the second quality video stream, and the stored plurality of video streams When any one of them is specified and a playback request for a specific video is received, the real-time output of the first extension layer data other than the video stream specified by the playback request is stopped, and the video stream specified by the playback request is stopped. When reading and outputting the second extension layer data of a specific video from the accumulation result of the transmission processing device,
The video reproduction requesting means transmits any one of a plurality of video streams accumulated by the transmission side accumulating means and a reproduction request for the specific video to the transmission processing device,
The layer synthesizing unit synthesizes the basic layer data and the first enhancement layer data of the plurality of video streams separated and decoded by the reception processing unit when the real-time video stream is output. Real-time video according to quality is generated, and when a specific video playback request of the specified video stream is requested by the video playback requesting means, the basic layer data and the first extension of the specific video of the video stream specified by the playback request The layer data is read out from the receiving-side storage unit and combined with the second extension layer data of the specific video of the designated video stream that is separated and decoded by the reception processing unit, and the identification based on the third quality is performed. The reception processing apparatus according to claim 5, wherein the video is generated. In a video transmission method when receiving and displaying a real-time video stream transmitted from the transmission side on the reception side,
The sender side
The video stream is a difference between a basic layer data that is a first quality video, a second quality video that is higher than the first quality, and a first quality video. Divided into the extension layer data, and the second extension layer data that is the difference between the third quality video and the second quality video that are higher in quality than the second quality,
The base layer data, the video of a plurality of layer data divided and encoded into the first and second extension layer data is accumulated on the transmission side,
The basic layer data and the first extended layer data among the plurality of layer data are output in real time as the second quality video stream, and the reproduction request for the specific video stored on the transmission side is received from the reception side. And stopping the real-time output of the first extension layer data, and outputting the second extension layer data of the specific video that has received the reproduction request,
Transmitting multiplexed data obtained by multiplexing the plurality of hierarchical data to be output to the receiving side ;
The receiving side
Separating and decoding the plurality of hierarchical data from the multiplexed data transmitted by the transmission side;
Storing a plurality of hierarchical data to be decoded;
Sending a playback request for a specific video stored on the transmission side to the transmission side,
When outputting the real-time video stream, the base layer data separated and decoded in the video stream reception process and the first extension layer data are synthesized to generate a real-time video image with the second quality, and the identification When the video playback request is received, the basic layer data and the first extension layer data of the specific video separated and decoded in the reception process are read out from the storage result on the receiving side and separated and decoded in the reception process. A video transmission method characterized in that the specific video is generated with the third quality by combining with the second extension layer data of the specific video.

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